2 event.c -- I/O, timeout and signal event handling
3 Copyright (C) 2014-2017 Guus Sliepen <guus@meshlink.io>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
25 #include "meshlink-tiny.h"
27 #include "splay_tree.h"
32 #if defined(CLOCK_MONOTONIC_RAW) && defined(__x86_64__)
33 #define EVENT_CLOCK CLOCK_MONOTONIC_RAW
35 #define EVENT_CLOCK CLOCK_MONOTONIC
39 static void timespec_add(const struct timespec *a, const struct timespec *b, struct timespec *r) {
40 r->tv_sec = a->tv_sec + b->tv_sec;
41 r->tv_nsec = a->tv_nsec + b->tv_nsec;
43 if(r->tv_nsec > 1000000000) {
44 r->tv_sec++, r->tv_nsec -= 1000000000;
48 static void timespec_sub(const struct timespec *a, const struct timespec *b, struct timespec *r) {
49 r->tv_sec = a->tv_sec - b->tv_sec;
50 r->tv_nsec = a->tv_nsec - b->tv_nsec;
53 r->tv_sec--, r->tv_nsec += 1000000000;
57 static bool timespec_lt(const struct timespec *a, const struct timespec *b) {
58 if(a->tv_sec == b->tv_sec) {
59 return a->tv_nsec < b->tv_nsec;
61 return a->tv_sec < b->tv_sec;
65 static void timespec_clear(struct timespec *a) {
69 static int io_compare(const io_t *a, const io_t *b) {
73 static int timeout_compare(const timeout_t *a, const timeout_t *b) {
74 if(a->tv.tv_sec < b->tv.tv_sec) {
76 } else if(a->tv.tv_sec > b->tv.tv_sec) {
78 } else if(a->tv.tv_nsec < b->tv.tv_nsec) {
80 } else if(a->tv.tv_nsec > b->tv.tv_nsec) {
91 void io_add(event_loop_t *loop, io_t *io, io_cb_t cb, void *data, int fd, int flags) {
99 io_set(loop, io, flags);
101 splay_node_t *node = splay_insert_node(&loop->ios, &io->node);
106 void io_set(event_loop_t *loop, io_t *io, int flags) {
111 if(flags & IO_READ) {
112 FD_SET(io->fd, &loop->readfds);
114 FD_CLR(io->fd, &loop->readfds);
117 if(flags & IO_WRITE) {
118 FD_SET(io->fd, &loop->writefds);
120 FD_CLR(io->fd, &loop->writefds);
124 void io_del(event_loop_t *loop, io_t *io) {
127 loop->deletion = true;
131 splay_unlink_node(&loop->ios, &io->node);
135 void timeout_add(event_loop_t *loop, timeout_t *timeout, timeout_cb_t cb, void *data, struct timespec *tv) {
137 timeout->data = data;
139 timeout_set(loop, timeout, tv);
142 void timeout_set(event_loop_t *loop, timeout_t *timeout, struct timespec *tv) {
145 if(timeout->node.data) {
146 splay_unlink_node(&loop->timeouts, &timeout->node);
148 timeout->node.data = timeout;
151 if(!loop->now.tv_sec) {
152 clock_gettime(EVENT_CLOCK, &loop->now);
155 timespec_add(&loop->now, tv, &timeout->tv);
157 if(!splay_insert_node(&loop->timeouts, &timeout->node)) {
161 loop->deletion = true;
164 static void timeout_disable(event_loop_t *loop, timeout_t *timeout) {
165 if(timeout->node.data) {
166 splay_unlink_node(&loop->timeouts, &timeout->node);
167 timeout->node.data = NULL;
170 timespec_clear(&timeout->tv);
173 void timeout_del(event_loop_t *loop, timeout_t *timeout) {
178 if(timeout->node.data) {
179 timeout_disable(loop, timeout);
183 loop->deletion = true;
186 static int signal_compare(const signal_t *a, const signal_t *b) {
187 return (int)a->signum - (int)b->signum;
190 static void signalio_handler(event_loop_t *loop, void *data, int flags) {
193 unsigned char signum;
195 if(recv(loop->pipefd[0], &signum, 1, MSG_DONTWAIT) != 1) {
199 signal_t *sig = splay_search(&loop->signals, &(signal_t) {
204 #ifdef HAVE_STDATOMIC_H
205 atomic_flag_clear(&sig->set);
207 sig->cb(loop, sig->data);
211 static struct sockaddr_in loopback = {0};
213 static void pipe_init(event_loop_t *loop) {
214 meshlink_handle_t *mesh = loop->data;
216 loop->pipefd[0] = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
217 loop->pipefd[1] = loop->pipefd[0];
219 if(loop->pipefd[0] == -1) {
220 logger(mesh, MESHLINK_ERROR, "Could not create UDP socket");
224 loopback.sin_family = AF_INET;
225 loopback.sin_port = 1024;
226 loopback.sin_addr.s_addr = htonl(0x7F000001);
228 int result = bind(loop->pipefd[0], (struct sockaddr *)&loopback, sizeof(loopback));
231 logger(mesh, MESHLINK_ERROR, "Could not bind UDP socket to localhost");
236 fcntl(loop->pipefd[0], F_SETFL, O_NONBLOCK);
238 io_add(loop, &loop->signalio, signalio_handler, NULL, loop->pipefd[0], IO_READ);
242 static void pipe_exit(event_loop_t *loop) {
243 io_del(loop, &loop->signalio);
245 close(loop->pipefd[0]);
247 loop->pipefd[0] = -1;
248 loop->pipefd[1] = -1;
251 void signal_trigger(event_loop_t *loop, signal_t *sig) {
252 meshlink_handle_t *mesh = loop->data;
254 #ifdef HAVE_STDATOMIC_H
256 if(atomic_flag_test_and_set(&sig->set)) {
262 uint8_t signum = sig->signum;
263 sendto(loop->pipefd[1], &signum, 1, MSG_DONTWAIT, (struct sockaddr *)&loopback, sizeof(loopback));
267 void signal_add(event_loop_t *loop, signal_t *sig, signal_cb_t cb, void *data, uint8_t signum) {
272 sig->signum = signum;
273 sig->node.data = sig;
275 #ifdef HAVE_STDATOMIC_H
276 atomic_flag_clear(&sig->set);
279 if(loop->pipefd[0] == -1) {
283 if(!splay_insert_node(&loop->signals, &sig->node)) {
288 void signal_del(event_loop_t *loop, signal_t *sig) {
291 loop->deletion = true;
293 splay_unlink_node(&loop->signals, &sig->node);
296 if(!loop->signals.count && loop->pipefd[0] != -1) {
301 void idle_set(event_loop_t *loop, idle_cb_t cb, void *data) {
303 loop->idle_data = data;
306 static void check_bad_fds(event_loop_t *loop, meshlink_handle_t *mesh) {
307 // Just call all registered callbacks and have them check their fds
310 loop->deletion = false;
312 for splay_each(io_t, io, &loop->ios) {
313 if(io->flags & IO_WRITE) {
314 io->cb(loop, io->data, IO_WRITE);
321 if(io->flags & IO_READ) {
322 io->cb(loop, io->data, IO_READ);
329 } while(loop->deletion);
331 // Rebuild the fdsets
335 memcpy(&old_readfds, &loop->readfds, sizeof(old_readfds));
336 memcpy(&old_writefds, &loop->writefds, sizeof(old_writefds));
338 memset(&loop->readfds, 0, sizeof(loop->readfds));
339 memset(&loop->writefds, 0, sizeof(loop->writefds));
341 for splay_each(io_t, io, &loop->ios) {
342 if(io->flags & IO_READ) {
343 FD_SET(io->fd, &loop->readfds);
344 io->cb(loop, io->data, IO_READ);
347 if(io->flags & IO_WRITE) {
348 FD_SET(io->fd, &loop->writefds);
349 io->cb(loop, io->data, IO_WRITE);
353 if(memcmp(&old_readfds, &loop->readfds, sizeof(old_readfds))) {
354 logger(mesh, MESHLINK_WARNING, "Incorrect readfds fixed");
357 if(memcmp(&old_writefds, &loop->writefds, sizeof(old_writefds))) {
358 logger(mesh, MESHLINK_WARNING, "Incorrect writefds fixed");
362 bool event_loop_run(event_loop_t *loop, meshlink_handle_t *mesh) {
369 while(loop->running) {
370 clock_gettime(EVENT_CLOCK, &loop->now);
371 struct timespec it, ts = {3600, 0};
373 while(loop->timeouts.head) {
374 timeout_t *timeout = loop->timeouts.head->data;
376 if(timespec_lt(&timeout->tv, &loop->now)) {
377 timeout_disable(loop, timeout);
378 timeout->cb(loop, timeout->data);
380 timespec_sub(&timeout->tv, &loop->now, &ts);
386 it = loop->idle_cb(loop, loop->idle_data);
388 if(it.tv_sec >= 0 && timespec_lt(&it, &ts)) {
393 memcpy(&readable, &loop->readfds, sizeof(readable));
394 memcpy(&writable, &loop->writefds, sizeof(writable));
399 io_t *last = loop->ios.tail->data;
403 // release mesh mutex during select
404 pthread_mutex_unlock(&mesh->mutex);
407 int n = pselect(fds, &readable, &writable, NULL, &ts, NULL);
409 struct timeval tv = {ts.tv_sec, ts.tv_nsec / 1000};
410 int n = select(fds, &readable, &writable, NULL, (struct timeval *)&tv);
413 if(pthread_mutex_lock(&mesh->mutex) != 0) {
417 clock_gettime(EVENT_CLOCK, &loop->now);
420 if(sockwouldblock(errno)) {
426 logger(mesh, MESHLINK_ERROR, "Unrecoverable error from select(): %s", strerror(errno));
430 logger(mesh, MESHLINK_WARNING, "Error from select(), checking for bad fds: %s", strerror(errno));
431 check_bad_fds(loop, mesh);
442 // Normally, splay_each allows the current node to be deleted. However,
443 // it can be that one io callback triggers the deletion of another io,
444 // so we have to detect this and break the loop.
446 loop->deletion = false;
448 for splay_each(io_t, io, &loop->ios) {
449 if(FD_ISSET(io->fd, &writable) && io->cb) {
450 io->cb(loop, io->data, IO_WRITE);
457 if(FD_ISSET(io->fd, &readable) && io->cb) {
458 io->cb(loop, io->data, IO_READ);
470 void event_loop_start(event_loop_t *loop) {
471 loop->running = true;
474 void event_loop_stop(event_loop_t *loop) {
475 loop->running = false;
478 void event_loop_init(event_loop_t *loop) {
479 loop->ios.compare = (splay_compare_t)io_compare;
480 loop->timeouts.compare = (splay_compare_t)timeout_compare;
481 loop->signals.compare = (splay_compare_t)signal_compare;
482 loop->pipefd[0] = -1;
483 loop->pipefd[1] = -1;
484 clock_gettime(EVENT_CLOCK, &loop->now);
487 void event_loop_exit(event_loop_t *loop) {
488 assert(!loop->ios.count);
489 assert(!loop->timeouts.count);
490 assert(!loop->signals.count);
492 for splay_each(io_t, io, &loop->ios) {
493 splay_unlink_node(&loop->ios, splay_node);
496 for splay_each(timeout_t, timeout, &loop->timeouts) {
497 splay_unlink_node(&loop->timeouts, splay_node);
500 for splay_each(signal_t, signal, &loop->signals) {
501 splay_unlink_node(&loop->signals, splay_node);